Toll-like receptors (TLRs) recognize and respond to conserved motifs termed pathogen-associated molecular patterns (PAMPs). TLRs are characterized by an extracellular leucine-rich repeat motif and an intracellular Toll/IL-1 receptor (TIR) domain. Triggering of TLRs by PAMPs initiates a series of intracellular signaling events resulting in an inflammatory immune response designed to contain and eliminate the pathogen. Viruses encode immunoregulatory proteins, such as A52R (produced by the vaccinia virus), that can effectively inhibit intracellular TIR signaling resulting in a diminished inflammatory immune response.
Chronic otitis media (COM) affects both children and adults. The chronic inflammation seen in COM can impact the inner ear and can lead to sensorineural hearing loss. COM is a significant medical problem, and no current therapeutics, other than steroids, are available for treating COM. Many patients with COM require surgical placement of ear tubes. As with acute otitis media (AOM), patients with COM experience decreased hearing due to development of an intense inflammatory response within the middle ear, including the presence of residual fluid.